CBWFQ and offered rate

[m.baker]

Hi,

Couple of questions about CBWFQ ;

1) Is it normal for offered rate to go higher then the bandwidth of my interface ?

2) On a 7513 router with an ATM OC3, if I configure my Classes as a percentage, the calculated number of Kbps allocated to each class seems higher then what it should. It this because the router accounts for the ATM cell overhead ?

Thanks

[bbranch]

On ATM interfaces the Layer-3 queuing mechanism does not take into accout the cell overhead i.e. a 64 byte packet is couted as 64 by CBWFQ but as 106 by the ATM interace - 2 x 53 Byte Cells.

There is a good doc on CCO covering ATM overhead and CBWFQ:

What Bytes Are Counted by IP to ATM CoS Queueing -

http://www.cisco.com/en/US/partner/tech/tk39/tk824/technologies_tech_note09186a00800942f5.shtml